The two objectives of the project are to assess the determinants of Community Health Centers' involvement in managed care and the impact of managed care on Community Health Centers (CHCs). Such knowledge is critical for the continued success of CHCs' in carrying out their mission to serve the nation's underserved and vulnerable populations. The project employs secondary analysis of an administrative, longitudinal database, the Uniform Data System (UDS) and its predecessor the Bureau Common Reporting Requirements (BCRR) maintained by the Bureau of Primary Health Care (BPHC). We will use 1991-1997 data for this project including 1991-1995 BCRR and 1996-1997 UDS. There are approximately 600 BPHC-funded CHCs in each year. The BCRR and UDS datasets will be linked via a common field: grantee's unique BCRR or UDS number. A series of multivariate analyses, including logistic regressions, multiple regressions, Tobit models, and a multinomial logistic regression model, will be performed to assess both external environmental and internal organizational determinants of CHCs' involvement in managed care. External factors include state Section 1115 waiver status, percent of revenue from grant funding, percent of revenue from Medicaid, and rural/urban location. Internal factors include center size and Medicaid patients as a proportion of total users. Rates of change in percent of revenue from grant funding, Medicaid, and changes in proportion of Medicaid patients are included in the analyses to capture the impact of trend. The generalized estimating equation (GEE) methods for longitudinal data will be used as the main tools for the data analyses. Both bivariate and multivariate analyses will be conducted to examine the impact of managed care on CHC outcomes. In the bivariate analyses, ANOVA and Post-hoc means tests will be performed for each year to a assess the relation between level of managed care involvement and CHC outcomes. In multivariate analyses, pooled cross-sectional longitudinal analyses ("growth models") will be used to examine the impact of managed care status on pattern-changes of CHC outcome measures over time. CHC outcome variables include the proportion of uninsured patients, vulnerable patients, proportion of expenses used for enabling services, and financial stability, efficiency, and productivity measures.